1. Field of the Invention
This invention generally relates to an electronic still video camera and in particular to an improved electronic still camera which converts a still picture of an object or scene into an operator selectable compressed digital signal format for storage utilizing a compression/decompression algorithm, such as the Joint Photographic Experts Group (JPEG) algorithm standard for example, formatted into Personal Computer (PC) compatible format retaining the images' color information, and stored on a PC compatible memory diskette. For example, the diskette can be a three and a half (31/2) inch digital diskette. The digital diskette is removeable from the electronic camera for direct insertion into a PC which contains the previously loaded corresponding decompression algorithm whereby the digital image is in a format compatible for immediate use with word processing, desk top publishing, data base, and multi-media applications.
2. Description of the Prior Art
FIG. 1 is a schematic block diagram showing structure of a conventional prior art electronic still camera system, in which a CCD image sensor element 1a converts a still image of an object into an analog color video signal when the shutter control circuitry 2a is activated. The output color video signal of the image sensor element is then routed to the signal processing subsystem 3a where the signal is converted to National Television System Committee (NTSC) or other composite video formats (such as the European video standard Phase Alternating Line-PAL) and logged in analog format onto a mass memory storage device such as an analog video floppy disk, Electrically Erasable Programmable Read Only Memory (EEPROM), analog audio cassette, bubble memory, or other storage device 5a. Power is supplied by a rechargeable/removeable battery system 4a.
An electronic camera that converts an image into electronic image signals and transferred to a memory storage device is disclosed in the following: U.S. Pat. No. 4,131,919; U.S. Pat. No. 4,456,931; U.S. Pat. No. 4,758,883; U.S. Pat. No. 4,803,554; and U.S. Pat. No. 4,837,628.
Conventional prior art electronic still cameras, for example of the types disclosed in the aforementioned references, produce an electronic signal corresponding to a desired image in analog format such as the National Television System Committee (NTSC) or similar on magnetic or electronic storage media for either permanent or temporary storage to facilitate viewing on a television or video monitor. With the current state of the art, it is expensive and time consuming to convert the analog image equivalent to a digital format for direct utilization with PC software applications. Currently, to convert an image captured on an electronic still camera to a PC compatible format one must convert the signal back to either a composite NTSC or RGB video signal and use a conversion device such as a "frame grabber" (a digital circuit board installed into PCs that convert video images into PC compatible formats) of the type sold commercially by Aapps Corporation, Orange Micro, RasterOps, and others or convert the image to a hard-copy print (a photograph) and utilize an electronic "scanner", a piece of equipment that connects to a PC, which converts an image into a digital format. The later technique is employed extensively within the desktop publishing industry.